The present invention relates to a device for varying the height of a bed in a fluidized combustion chamber inside a pressurized housing by supplying bed material to the chamber from hoppers or by returning the bed material back to the hoppers from the chamber through a supply line that connects the chamber and the hoppers, which have means of increasing or decreasing the pressure.
The fluidized combustion chamber in a device of this type that is known from EP OS No. 0 124 842 communicates with a hopper through two lines. The out-thrust line communicates with the hopper through a cyclone precipitator and is maintained at low pressure. Another line that is maintained at low pressure opens into a separate return line. Both pressurized lines have valves. Thus, the known device for varying the height of bed is expensive.